Wireless relay system, wireless relay method and base station apparatus

Abstract

Provided is a wireless relay system including multiple terminal station apparatuses and a base station apparatus. The base station apparatus includes: a base station reception unit that respectively receives pieces of upstream data traffic from the multiple terminal station apparatuses; an encoding unit that, if pieces of upstream data traffic that require mutual forwarding in opposite directions are present in the respective pieces of upstream data traffic, performs network encoding on the respective pieces of upstream data traffic such that the pieces of upstream data traffic are pieces of data traffic of mutually identical content; and a base station transmission unit that simultaneously transmits encoded data traffic as downstream data traffic to the multiple terminal station apparatuses. The terminal station apparatuses each include: a terminal station transmission unit that transmits the upstream data traffic to the base station apparatus; a terminal station reception unit that receives the encoded data traffic; and a decoding unit that decodes the encoded data traffic using the upstream data traffic.

The invention claimed is: 
     
       1. A wireless relay system including a plurality of terminal station apparatuses and a base station apparatus configured to relay data traffic transmitted through wireless communication between the plurality of terminal station apparatuses, wherein the base station apparatus includes:
 a processor; and 
 a storage medium having computer program instructions stored thereon, when executed by the processor, perform to: 
 receive pieces of upstream data traffic from the plurality of terminal station apparatuses; if the pieces of upstream data traffic that require mutual forwarding in opposing directions between the plurality of terminal station apparatuses are present in the respective pieces of upstream data traffic, perform network encoding on the respective pieces of upstream data traffic such that the pieces of upstream data traffic are pieces of data traffic of mutually identical content; and simultaneously transmit pieces of encoded data traffic indicating the pieces of data traffic subjected to network encoding as downstream data traffic to the plurality of terminal station apparatuses that transmitted the pieces of upstream data traffic, and 
 wherein the terminal station apparatuses each include: 
 a processor; and 
 a storage medium having computer program instructions stored thereon, when executed by the processor, perform to: 
 transmit the upstream data traffic to the base station apparatus; receive the pieces of encoded data traffic transmitted from the base station apparatus; and decode the pieces of encoded data traffic using the upstream data traffic. 
 
     
     
       2. The wireless relay system according to  claim 1 , wherein the computer program instructions of the base station apparatus further performs network encoding by calculating exclusive-OR for a bit string of the pieces of upstream data traffic, and the decoding unit performs decoding by calculating exclusive-OR for the pieces of encoded data traffic and the upstream data traffic. 
     
     
       3. The wireless relay system according to  claim 1 , wherein the computer program instructions of the base station apparatus further perform to transmits the pieces of encoded data traffic to the plurality of terminal station apparatuses by performing beam forming. 
     
     
       4. The wireless relay system according to  claim 1 , wherein the base station apparatus performs communication with the plurality of terminal station apparatuses using a communication scheme according to a space-division multiple access scheme. 
     
     
       5. The wireless relay system according to  claim 1 , wherein the base station apparatus and the terminal station apparatuses perform communication with each other using a communication scheme according to a time-division duplexing scheme. 
     
     
       6. The wireless relay system according to  claim 1 , wherein the data traffic includes a control signal to be used for handover between the plurality of terminal station apparatuses. 
     
     
       7. A wireless relay method performed by a wireless relay system including a plurality of terminal station apparatuses and a base station apparatus configured to relay data traffic transmitted through wireless communication between the plurality of terminal station apparatuses, the method comprising: a terminal station transmission step in which the terminal station apparatuses transmit pieces of upstream data traffic to the base station apparatus; a base station reception step in which the base station apparatus receives the pieces of upstream data traffic from the plurality of terminal station apparatuses; an encoding step in which, if the pieces of upstream data traffic that require mutual forwarding in opposing directions between the plurality of terminal station apparatuses are present in the respective pieces of upstream data traffic received through the base station reception step, the base station apparatus performs network encoding on the respective pieces of upstream data traffic such that the pieces of upstream data traffic are pieces of data traffic of mutually identical content; a base station transmission step in which the base station apparatus simultaneously transmits respective pieces of encoded data traffic indicating the pieces of data traffic subjected to network encoding through the encoding step as downstream data traffic to the plurality of terminal station apparatuses that transmitted the pieces of upstream data traffic; a terminal station reception step in which the terminal station apparatuses receive the pieces of encoded data traffic transmitted from the base station apparatus; and a decoding step in which the terminal station apparatuses decode the pieces of encoded data traffic received through the terminal station reception step using the pieces of upstream data traffic transmitted through the terminal station transmission step. 
     
     
       8. A base station apparatus configured to relay data traffic transmitted through wireless communication between a plurality of terminal station apparatuses, the base station apparatus comprising:
 a processor; and 
 a storage medium having computer program instructions stored thereon, when executed by the processor, perform to: 
 receive pieces of upstream data traffic from the plurality of terminal station apparatuses; if the pieces of upstream data traffic that require mutual forwarding in opposing directions between the plurality of terminal station apparatuses are present in the respective pieces of upstream data traffic, perform network encoding on the respective pieces of upstream data traffic such that the pieces of upstream data traffic are pieces of data traffic of mutually identical content; and simultaneously transmit pieces of encoded data traffic indicating the pieces of data traffic subjected to network encoding as downstream data traffic to the plurality of terminal station apparatuses that transmitted the pieces of upstream data traffic.